U.S. patent application number 09/803343 was filed with the patent office on 2002-11-14 for phase stable polyol composition containing hydrocarbon as the blowing agent.
Invention is credited to Patterson, Jim, Riley, Robert E., White, Walter R. III.
Application Number | 20020169228 09/803343 |
Document ID | / |
Family ID | 25186288 |
Filed Date | 2002-11-14 |
United States Patent
Application |
20020169228 |
Kind Code |
A1 |
Riley, Robert E. ; et
al. |
November 14, 2002 |
PHASE STABLE POLYOL COMPOSITION CONTAINING HYDROCARBON AS THE
BLOWING AGENT
Abstract
The present invention discloses a phase stable polyol blend
composition containing a sucrose and dipropylene glycol
co-initiated propylene oxide polyether polyol, a polyester polyol,
a compatibilizing agent and a hydrocarbon blowing agent. The
polyester polyol is preferably a phthalic anhydride-initiated
polyester polyol. The compatibilizing agent is a butanol-initiated
propylene oxide polyether surfactant.
Inventors: |
Riley, Robert E.; (Flat
Rock, MI) ; White, Walter R. III; (Trenton, MI)
; Patterson, Jim; (New Boston, MI) |
Correspondence
Address: |
BASF CORPORATION
LEGAL DEPARTMENT
1609 BIDDLE AVENUE
WYANDOTTE
MI
48192
US
|
Family ID: |
25186288 |
Appl. No.: |
09/803343 |
Filed: |
March 9, 2001 |
Current U.S.
Class: |
521/131 ;
252/182.24; 252/182.25; 252/182.27; 252/182.29; 521/173;
521/174 |
Current CPC
Class: |
C08G 2110/0025 20210101;
C08G 2130/00 20130101; C08J 2375/04 20130101; C08G 18/482 20130101;
C08J 9/141 20130101; C08G 18/4018 20130101; C08G 2110/005
20210101 |
Class at
Publication: |
521/131 ;
521/173; 521/174; 252/182.24; 252/182.25; 252/182.27;
252/182.29 |
International
Class: |
C08J 009/00 |
Claims
What is claimed is:
1. A polyol blend composition comprising: a) a sucrose and
dipropylene co-initiated propylene oxide polyether polyol; b) a
polyester polyol; c) a compatibilizing agent comprising a
butanol-initiated propylene oxide polyester surfactant; and d) a
hydrocarbon blowing agent comprising C.sub.4-C.sub.6 hydrocarbons
and mixtures thereof; and wherein said polyol blend composition is
phase stable for at least 24 hours after blending components
a)-d).
2. The polyol blend composition of claim 1, wherein the sucrose and
dipropylene glycol co-initiated polyol is present in an amount of
from 30 to 80 parts by weight based on the total weight of the
polyol blend composition.
3. The polyol blend composition of claim 1, wherein the polyester
polyol comprises a phthalic anhydride-initiated polyester
polyol.
4. The polyol blend composition of claim 3, wherein the phthalic
anhydride-initiated polyol is present in an amount of from 15 to 25
parts by weight based on the total weight of the polyol blend
composition.
5. The polyol blend composition of claim 1, wherein the
compatibilizing agent is present in an amount of from 10 to 20
parts by weight based on the total weight of the polyol blend
composition.
6. The polyol blend composition of claim 1, wherein the hydrocarbon
blowing agent is present in an amount of from 10 to 20 parts by
weight based on the total weight of the polyol blend
composition.
7. The polyol blend composition of claim 1, wherein the hydrocarbon
blowing agent comprises normal pentane.
8. The polyol blend composition of claim 1, further including a
second polyether polyol other than the sucrose and dipropylene
co-initiated propylene oxide polyether polyol.
9. The polyol blend composition of claim 8, wherein the second
polyether polyol comprises a toluene diamine-initiated propylene
oxide polyether polyol.
10. The polyol blend composition of claim 1, further comprising at
least one of a flame retardant, a cross-linking agent, a chain
extender, an ultraviolet stabilizer, a surfactant or a filler.
11. A polyol blend composition comprising: a) a sucrose and
dipropylene glycol co-initiated propylene oxide polyether polyol;
b) a toluene diamine-initiated propylene oxide polyether polyol; c)
a phthalic anhydride-initiated polyester polyol; d) a
compatibilizing agent comprising a butanol-initiated propylene
oxide polyester surfactant; e) a hydrocarbon blowing agent
comprising a C.sub.4-C.sub.6 hydrocarbon and mixtures thereof; and
wherein said polyol blend composition is phase stable for at least
24 hours after blending components a)-e).
12. The polyol blend composition of claim 11, wherein the sucrose
and dipropylene glycol co-initiated polyol is present in an amount
of from 30 to 80 parts by weight based on the total weight of the
polyol blend composition.
13. The polyol blend composition of claim 11, wherein the
compatibilizing agent is present in an amount of from 10 to 20
parts by weight based on the total weight of the polyol blend
composition.
14. The polyol blend composition of claim 11, wherein the
hydrocarbon blowing agent is present in an amount of from 10 to 20
parts by weight based on the total weight of the polyol blend
composition.
15. The polyol blend composition of claim 11, wherein the toluene
diamine-initiated polyether polyol is present in an amount of from
15 to 25 parts by weight based on the total weight of the polyol
blend composition.
16. The polyol blend composition of claim 11, further comprising at
least one of a flame retardant, a cross-linking agent, a chain
extender, an ultraviolet stabilizer, a surfactant or a filler.
17. A polyurethane foam comprising the reaction product of an
organic polyisocyanate and a polyol blend composition comprising:
a) a sucrose and dipropylene co-initiated propylene oxide polyether
polyol; b) a polyester polyol; c) a compatibilizing agent
comprising a butanol-initiated propylene oxide polyester
surfactant; and d) a hydrocarbon blowing agent comprising
C.sub.4-C.sub.6 hydrocarbons and mixtures thereof; wherein said
polyol blend composition is phase stable for at least 24 hours
after blending components a)-d) of said polyol blend
composition.
18. The foam of claim 17, wherein the sucrose and dipropylene
glycol co-initiated polyol is present in an amount of from 30 to 80
parts by weight based on the total weight of the polyol blend
composition.
19. The foam of claim 17, wherein the polyester polyol comprises a
phthalic anhydride-initiated polyester polyol in an amount of from
15 to 25 parts by weight based on the total weight of the polyol
blend composition.
20. The foam of claim 17, wherein the compatibilizing agent is
present in an amount of from 10 to 20 parts by weight based on the
total weight of the polyol blend composition.
21. The foam of claim 17, wherein the hydrocarbon blowing agent
comprises normal pentane in an amount of from 10 to 20 parts by
weight based on the total weight of the polyol blend
composition.
22. The foam of claim 17, wherein the polyol blend composition
further comprises a second polyether polyol which comprises a
toluene diamine-initiated propylene oxide polyether polyol.
23. The foam of claim 17, wherein the polyol blend composition
further comprises at least one of a flame retardant, a
cross-linking agent, a chain extender, an ultraviolet stabilizer, a
surfactant or a filler.
Description
FIELD OF THE INVENTION
[0001] This invention generally relates to dimensionally stable
polyurethane/polyiscyanurate foams and to polyol blends used to
make such foams. Particularly, the present invention relates to
polyol blends comprising a co-initiated propylene oxide polyether
polyol, a polyester polyol, a hydrocarbon blowing agent and a
compatibilizing agent.
BACKGROUND OF THE INVENTION
[0002] Due to environmental legislation restricting the use of
chloroflorocarbons and hydrochloroflorocarbons as blowing agents,
hydrocarbons are being employed in greater numbers as viable
alternative blowing agents in the manufacture of rigid polyurethane
or polyisocyanurate foams. Hydrocarbons are readily available and
provide a cost-effective alternative to chloroflorocarbons and
hydrochloroflorocarbons.
[0003] Due to the non-polar hydrophobic characteristics of
hydrocarbons, they are only partially soluble in many polyols used
to manufacture rigid polyurethane or polyisocyanurate foams. As a
result of the poor solubility of hydrocarbon blowing agents, the
blowing agent must usually be added to the polyol just prior to
dispensing it through a mix head. The limited shelf life of
hydrocarbon-polyol mixtures has limited the ability of storing
batches for later use.
[0004] Another problem with these mixtures is their potential
limited process phase stability or limited resistance to separation
into layers of different composition. If there is a phase
separation during the process, the hydrocarbon blowing agent has
the tendency to rise to the top of the mixture and vaporize;
thereby posing a potential safety hazard should the concentration
of the hydrocarbon reach the explosion limit.
[0005] A phase separation during the process often causes
non-uniform and uneven cell structures in the resultant
polyurethane or polyisocyanurate foam. Such non-uniform cell
structure can lead to variations in the properties of a foam
product, such as the thermal conductivity or insulation value
(R-factor). It would be undesirable to have such variations,
particularly for foams utilized for insulation applications. The
density of the foam may also be affected by the phase separation,
leading to undesirable physical characteristics, such as increased
hardness or brittleness.
SUMMARY OF THE INVENTION
[0006] There is provided a phase stable polyol blend composition
comprising a polyether polyol, a polyester polyol, a
compatibilizing agent and a hydrocarbon blowing agent. The polyol
blend components including the hydrocarbon blowing agent forms a
micro-emulsion and is therefore soluble and phase stable in the
polyol blend. Upon forming a substantially homogeneous blend of the
composition's components, the composition remains phase stable for
at least 24 hours.
[0007] In one embodiment, the polyether polyol component comprises
a sucrose and dipropylene glycol co-initiated propylene oxide
polyether polyol.
[0008] In another embodiment, the polyester polyol utilized in the
invention is a phthalic anhydride-initiated polyol.
[0009] The hydrocarbon blowing agents in the composition are
C.sub.4-C.sub.6 hydrocarbons or mixtures thereof. The pentanes are
particularly preferred and are present in the polyol blend in
amounts of from 20 to 30 parts by weight based on the total weight
of the polyol composition.
[0010] The compatibilizing agents useful in the present invention
are butanol-initiated propylene oxide polyester surfactants.
[0011] In another embodiment, an additional polyether polyol may be
used as a substitute for the polyester polyol or may be combined
with the composition. The additional polyether polyol is preferably
a TDA-initiated propylene oxide polyether polyol.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0012] The phase stable polyol blend of the present invention
includes a propylene oxide polyether polyol, a polyester polyol, a
compatibilizing agent and a hydrocarbon blowing agent.
[0013] The phase stable polyol blend is deemed to be phase stable
when the blend composition has the capacity of retaining the
hydrocarbon blowing agent in solution for a specified period of
time; generally at least 24 hours, after blending the polyol
composition components. Generally, a determination as to the phase
stability of the composition is measured by mixing the hydrocarbon
blowing agent with the propylene oxide polyether polyol, polyester
polyol, and compatibilizing agent in a clear container having a
lid. The container is then agitated vigorously to fully mix the
composition, and the container is allowed to stand undisturbed for
at least a 24-hour period. If there is no visible phase separation
into distinct layers, or a cloudy appearance, then the composition
is deemed to be phase stable.
[0014] Methods of forming polyoxyalkylene polyether polyols are
well known, for example, by the base catalyzed addition of alkylene
oxides to an initiator molecule containing reactive hydrogens such
as a polyhydric alcohol. In one embodiment of the present
invention, the initiator molecules are a combination, mixture or
blend of a diol and a sugar. Other examples of such initiators
include: glycerol; 1,1,1-trimethylolpropane;
1,1,1-trimethylolethane; 1,2,6-hexanetriol; pentaerythritol; and
sorbitol. Other suitable initiators include both aliphatics and
aromatics, such as ethylene glycol, propylene glycol, dipropylene
glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol,
1,4-butanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol,
1,6-hexanediol, 1,7-heptanediol. Also included within the term
"polyhydric alcohol" are compounds derived from phenol such as
2,2-bis(4-hydroxyphenyl)propane, commonly known as Bisphenol A. The
polyether polyols may be prepared by any known process such as, for
example, the process disclosed by Wurtz in 1859, Encyclopedia of
Chemical Technology, Vol. 7, pp. 257-262, Published by Interscience
Publishers, Inc. (1951) or in U.S. Pat. No. 1,922,459, incorporated
herein by reference.
[0015] Examples of useful alkylene oxides include ethylene oxide,
propylene oxide, butylene oxide, amylene oxide, mixtures thereof,
tetrahydrofuran, alkylene oxide-tetrahydrofuran mixtures,
epihalohydrins, and aralkylene styrene. The alkylene oxides are
added onto the initiator molecule and chain propagation is carried
out in the presence of catalysts by either anionic polymerization
or by cationic polymerization.
[0016] The preferred catalysts are potassium hydroxide, sodium
hydroxide, alcoholates of potassium hydroxide, alcoholates of
sodium hydroxide, cesium catalysts, amines, Lewis acid catalysts,
or double metal complex catalysts, all of which are known in the
art.
[0017] The phase stable polyol blend of the present invention
contains a propylene oxide polyether polyol, a polyester polyol, a
compatibilizing agent, and a hydrocarbon blowing agent. Other
ingredients that may be included in the phase stable polyol blend
are additional polyols, catalysts, surfactants, other blowing
agents, flame retardants, fillers, stabilizers and other
additives.
[0018] The propylene oxide polyether polyol useful in accordance
with the present invention comprises a sucrose and dipropylene
glycol co-initiated polyoxyalkylene polyether polyol having only
propylene oxide as the alkylene oxide. It has been found that the
addition of other alkylene oxides, for example, ethylene oxide to
the initiator molecules may adversely affect the solubility of the
hydrocarbon blowing agent in the polyol composition.
[0019] The sucrose and dipropylene glycol co-initiated polyol
preferably has a nominal functionality between 4 and 5, even more
preferably of 4.4. The co-initiated polyol has a hydroxyl number
from 250 to 400 meq polyol/g KOH. Even more preferably, the polyol
has a hydroxyl number of from 300 meq polyol/g KOH to 400 meq
polyol/g KOH. The sucrose and dipropylene glycol co-initiated
polyol is preferably present in an amount of from 30 to 80 parts by
weight based on the overall weight of all components of the phase
stable polyol blend.
[0020] In one embodiment of the present invention an additional
polyether polyol, a toluene diamine (TDA)-initiated polyoxyalkylene
polyether polyol having only propylene oxide as the alkylene oxide
may be included. The TDA-initiated polyol, preferably has a
hydroxyl number of from between 350 meq polyol/g KOH and 450 meq
polyol/g KOH, and a nominal functionality between 3.5 and 4.5. The
TDA-initiated polyol is preferably present in an amount of from 15
to 25 parts by weight based on the overall weight of all components
of the phase stable polyol composition.
[0021] The polyester polyol of the phase stable polyol blend of the
present invention is preferably a phthalic anhydride-initiated
polyester polyol. Preferably, the polyester polyol has a hydroxyl
number of from 200 to 300 meq polyol/g KOH.
[0022] A particularly preferred polyester polyol of the present
invention includes STEPANPOL( PS 2352, a phthalic
anhydride-initiated polyester polyol commercially available from
Stepan Chemical Company (Northfield, Ill.).
[0023] The overall amount of the polyester polyol is preferably
between 15 and 25 parts by weight based on the overall weight of
all components of the phase stable polyol blend. Even more
preferably the polyester polyol is present in an amount between 17
and 23 parts by weight based on the overall weight of all
components of the phase stable polyol blend.
[0024] The compatibilizing agent of the present invention is a
butanol-initiated polyoxyalkylene polyether surfactant. As with the
aforementioned polyether polyols, the compatibilizing agent
preferably only has propylene oxide as the alkylene oxide portion.
The compatibilizing agent preferably has a hydroxyl number of from
100 to 200 meq surfactant/g KOH.
[0025] A particularly preferred compatibilizing agent of the
present invention includes Ortegol.RTM. 410, a butanol-initiated
polyether surfactant commercially available from Goldschmidt
Corporation.
[0026] The overall amount of the compatibilizing agent can be from
about 10 to 30 parts by weight, and is preferably between 10 and 20
parts by weight, more preferably between 12 and 16 parts by weight,
based on the overall weight of all components of the phase stable
polyol blend. Even more preferably, the compatibilizing agent is
present in an amount of about 14 parts by weight based on the
overall weight of all components of the phase stable polyol
blend.
[0027] In addition to the foregoing, the phase stable polyol blend
of the present invention includes a blowing agent comprising a
C.sub.4-C.sub.6 hydrocarbon and mixtures thereof. The blowing agent
may be added and incorporated into the polyol blend for storage and
later use in a foaming apparatus or may be added to a preblend tank
in the foaming apparatus and incorporated in the polyol blend prior
to pumping the foaming ingredients to the mixhead. Alternatively,
the blowing agent may be added to the foaming ingredients in the
mixhead as a separate stream.
[0028] Generally, the amount of blowing agent in the polyol blend
can be from about 10 to 30 parts by weight, and is preferably from
10 to 20 parts by weight, even more preferably approximately 15
parts by weight based on the total weight of all components in the
polyol blend composition.
[0029] Examples of C.sub.4-C.sub.6 hydrocarbon blowing agents
include butanes, pentanes, hexanes and mixtures thereof. Preferred
blowing agents are the pentanes including isopentane, normal
pentane, cyclopentane, and neopentane. The pentanes may be
incorporated into the phase stable polyol blend of the present
invention alone or as a mixture of two or more of the pentanes. For
example, normal pentane mixed with isopentane or cyclopentane may
be utilized by the present invention. It is less desirable to
utilize cyclopentane as the only blowing agent, as cyclopentane
reaches a saturation point quickly and therefor may form a
condensate during processing that may result in a poor cellular
structure for the foam. However, mixtures having cyclopentane as a
component may be utilized by the present invention.
[0030] The hydrocarbon blowing agents of the present invention are
generally available from manufacturers of fractional distillation
products from petroleum, including Phillips Petroleum and
ExxonMobil Corporation.
[0031] The polyol blend of the present invention may be utilized to
produce a polyisocyanurate or polyurethane foam. The isocyanate
component is preferably a polyisocyanate, herein defined as having
two or more isocyanate functionalities. Examples of these include
conventional aliphatic, cycloaliphatic, and preferably aromatic
isocyanates. Specific examples include: alkylene diisocyanates with
4,2,12 carbons in the alkylene radical such as 1,12-dodecane
diisocyanate, 2-ethyl-1,4-tetramethylene diisocyanate,
2-methyl-1,5-pentamethylene diisocyanate, 1,4-tetramethylene
diisocyanate and 1,6-hexamethylene diisocyanate; cycloaliphatic
diisocyanates such as 1,3- and 1,4-cyclohexane diisocyanate as well
as any mixtures of these isomers,
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane
(isophorone diisocyanate), 2,4- and 2,6-hexahydrotoluene
diisocyanate as well as the corresponding isomeric mixtures
4,4'-2,2'- and 2,4'-dicyclohexylmethane diisocyanate as well as the
corresponding isomeric mixtures and preferably aromatic
diisocyanates and polyisocyanates such as 2,4- and 2,6-toluene
diisocyanate and the corresponding isomeric mixtures, and
2,2'-diphenylmethane diisocyanate and the corresponding isomeric
mixtures, mixtures of 4,4'-, 2,4'-, and 2,2-diphenylmethane
diisocyanates and polyphenylene polymethylene polyisocyanates
(crude MDI).
[0032] In one embodiment, the polyisocyanate component used in
conjunction with the polyol blend of the present invention is a
polymeric diphenylmethane diisocyanate (MDI) having a nominal
functionality of approximately 3, and an NCO content of
approximately 31 weight percent.
[0033] A particularly preferred polyisocyanate component of the
present invention includes Lupranate.RTM. M70R, a polymeric MDI
commercially available from BASF Corporation (Mt. Olive, N.J.).
[0034] Generally, the isocyanate and the phase stable polyol blend
are combined at an isocyanate index of from 200 to 300, preferably
at 250, for polyisocyanurate rigid foams.
[0035] The catalysts used for the preparation of foams with the
polyol blend and isocyanate component are, in particular,
components that accelerate the reaction of the hydroxyl groups of
the polyol with the isocyanate groups. Suitable catalysts are
organic metal compounds, preferably organic tin compounds such as
tin (II) salts of organic carboxylic acids, e.g., tin (II) acetate,
tin (II) octoate, tin (II) ethylhexanate and tin (II) laurate, and
the dialkyltin (IV) salts of organic carboxylic acids, e.g.,
dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and
dioctyltin diacetate. The organic metal compounds are used alone or
preferably in combination with strongly basic amines. Examples
which may be mentioned are amines such as
2,3-dimethyl-3,4,5,6-tetrahydropyrimidine or tertiary amines such
as triethylamine, tributylamine; dimenthylbenzylamine;
N-methyhnorpholine; N-ethylmorpholine; N-cyclohexylmorpholine;
N,N,N', N'-tetramethylethylenediamine;
N,N,N',N'-tetramethylbutanediamine;
N,N,N',N'-tetramethylhexane-1,6-diamine;
pentamethyldiethylenetriamine; bis (dimethylaminoethyl) ether; bis
(dimethylaminopropyl) urea; dimethylpiperazine;
1,2-dimethylimidazole; 1-azabicyclo (3,3,0) octane and preferably
1,4-diazabicyclo (2,2,2) octane. Additionally, one can use
alkanolamine compounds such as triethanolamine;
triisopropanolamine; N-methyldiethanolamine and
N-ethyldiethanolamine and dimethylethanolamine.
[0036] Additional suitable catalysts include: tris
(dialkylaminoalkyl)-s-h- exahydrotriazines, in particular tris
(N,N-dimethylaminopropyl)-s-hexahydr- otriazine; tetraalkylammonium
hydroxides such as tetramethylammonium hydroxide; alkali metal
hydroxides such as sodium hydroxide and alkali metal alkoxides such
as sodium methoxide and potassium isopropoxide and also alkali
metal salts of long-chain fatty acids having from 10 to 20 carbon
atoms and possibly lateral OH groups in combinations of the organic
metal compounds and strongly basic amines. Preference is given to
using from 0.001 to 5% by weight, in particular from 0.05 to 2% by
weight, of catalysts or catalyst combination, based on the weight
of the polyol.
[0037] In one embodiment, suitable catalysts are organic metal
compounds, preferably organic potassium compounds such as potassium
salts of organic carboxylic acids, e.g., potassium acetate,
potassium octoate and potassium formate. The organic metal
compounds are used alone or preferably in combination with strongly
basic amines. Examples of such amines are,
2,3-dimethyle-3,4,5,6-tetrahydropyrimide or tertiary amines such as
triethylamine, tributylamine, dimenthybenzylamine. A particularly
preferred amine of the present invention is pentamethyl
diethylenetriamine (PMDEA).
[0038] Preferably the organic metal compound is present in an
amount of from 2 to 7 parts by weight based on the overall weight
of all components of the phase stable polyol blend, even more
preferably in an amount of from 2 to 3 parts by weight based on the
overall weight of all components of the phase stable polyol
blend.
[0039] Suitable surface-active substances that may also be added
include, for example, compounds, which serve to aid the
homogenization of the starting materials and also may be suitable
for regulating the cell structure. Examples which may be mentioned
are emulsifiers such as the sodium salts of castor oil sulfates or
fatty acids and also amine salts of fatty acids, e.g. Diethylamine
oleate, diethylamine sterate, diethylamine ricinoleate, salts of
sulfonic acid, e.g. Alkali metal or ammonium salts of
dodecylbenzene-or dinaphthylmethanedisulfonic acid and ricinoliec
acid; foam stabilizers such as siloxane-oxyalkylene copolymers and
other organopolysiloxanes, ethoxylated alkylphenols, ethoxylated
fatty alcohols, paraffin oils, castor oil or ricinoliec esters,
Turkey red oil and peanut oil. Additives may also include cell
regulators such as paraffins, fatty alcohols,
dimethylpolysiloxanes. Oligomeric polyacrylates having
polyoxyalkane and fluoroalkane radicals as side groups are also
suitable for improving the emulsifying action, the cell structure
and/or stabilizing the foam. The surface-active substances are
usually employed in amounts of from 0.01 to 5 parts by weight,
based on 100 parts by weight of the polyol components other than
the isocyanate component.
[0040] Suitable chain extender/crosslinkers that may be used
include diols and/or triols having molecular weights of less than
about 400. Examples of suitable chain extenders/crosslinkers are
aliphatic, cycloaliphatic and/or aromatic diols having from 2 to
14, preferably from 4 to 10, carbon atoms, e.g., ethylene glycol;
1,3-propanediol; 1,10-decanediol; o-, m-, p-dihydroxycyclohexane;
diethylene glycol; dipropylene glycol, and preferably
1,4-butanediol, 1,6-hexanediol and bis (2-hydroxyethyl)
hydroquinone, triols such as 1,2,4- and
1,3,5-trihydroxyclylohexane, and low molecular weight
hydroxyl-containing polyalkylene oxides based on ethylene oxide
and/or 1,2-propylene oxide in the above-mentioned diols and/or
triols as initiator molecules. These compounds are preferably used
in amounts of from 0 to 20% by weight based on the total weight of
the polyol blend.
[0041] Flame retardants that may be used include pentabromodiphenyl
oxide; dibromopropanol; tris (.beta.-chloropropyl) phosphate;
2,2-bis (bromoethyl) 1,3-propanediol; tetrakis (2-chloroethyl)
ethylene diphosphate; tris (2,3-dibromopropyl) phosphate; tris
(.beta.-chloroethyle) phosphate; tris (1,2-dichloropropyl)
phosphate; bis-(2-chloroethyl) 2-chloroethylphosphonate;
molybenumtrioxide; ammonium molybdate; ammonium phosphate;
pentabromodiphenyloxide; tricresyl phosphate;
hexabromocyclododecane; melamine; and dibromoethyldibromocyclo-
hexane. Concentrations of flame retardant compounds, which may be
employed range from 15 to 25 parts based on the total weight of the
polyol blend.
[0042] The foam may further include fillers such as organic,
inorganic and reinforcing fillers. Specific examples are: inorganic
fillers such as siliceous minerals, for example, sheet silicates
such as antigorite, serpentine, hornblends, amphiboles, chrysotile,
zeolites, talc; metal oxides, such as kaolin, aluminum oxides,
titanium oxides and iron oxides, meta salts, such as chalk, barite,
aluminum silicates and inorganic pigments such as cadmium sulfide,
zinc sulfide, and also glass particles. Examples of organic fillers
are: carbon black, melamine, rosin, cyclopentadienyl resins. The
organic and inorganic fillers can be used individually or as
mixtures and are advantageously incorporated into the reaction
mixture in amounts of from 0.5 to 50% by weight based on the weight
of the polyol and the isocyanate component.
[0043] To form the foam of the present invention the phase stable
polyol blend, catalyst and any other components other than the
polyisocyanate component are premixed to form a resin. After
formation of the resin, the resin is combined in a mixhead with the
polyisocyanate component and the mixture is processed by any of the
methods commonly known in the art to form a foam.
EXAMPLES
[0044] In the following examples, Polyether polyol A is a sucrose
and dipropylene glycol co-initiated polyol having only propylene
oxide as the alkylene oxide portion of the polyol. Polyether polyol
B is a toluene diamine (TDA)-initiated polyol having only propylene
oxide as the alkylene oxide portion of the polyol. The
compatibilizing agent is a butanol-initiated all-propylene oxide
polyether surfactant. Potassium octoate is an organo-metal
catalyst. Blowing catalyst is a pentamethyl diethylenetriamine
catalyst. Polyester polyol is a phthalic anhydride-initiated
polyester polyol. Flame retardant is a tris (2-chloropropyl)
phosphate flame retardant. Hydrocarbon blowing agent is normal
pentane. Isocyanate is a polymeric MDI isocyanate.
1 Parts by Weight Components 1 2 3 4 Polyether Polyol A 70 70 60 60
Polyether Polyol B 0 30 0 40 Compatibilizing Agent 25 25 25 25
Surfactant (B8462) 4 4 4 4 Potassium Octoate 5 5 5 5 Blowing
Catalyst (PC5) .5 .5 .5 .5 Polyester Polyol 30 0 0 0 Flame
Retardant 15 15 15 15 Hydrocarbon Blowing Agent 26 28 25.7 28.5
Isocyanate 192.24 219.42 188.61 224.86 Isocyanate Index 250 250 250
250 Reactivity: (Time in minutes) Mix 5 5 5 5 Cream 10 13 9 11 Gel
21 25 18 18 Tack Free 30 36 26 26 Cup Density (PCF) 1.9 2.1 2.0
2.0
[0045] All of the components, with the exception of the isocyanate
are premixed to form a polyol resin. The resin is then mixed with
the isocyanate at the index indicated to form a foam and the foam
is allowed to free rise and cure.
[0046] As can be seen from the preceding table, various
combinations of the aforementioned components may be utilized to
produce dimensionally stable foams. The reactivity properties of
the various compositions are recorded in the table, detailing the
mix, cream, gel, and tack free times of the various compositions.
The densities of the foams produced for the various compositions
are also recorded in the table. The resulting composition exhibits
a phase stable polyol blend that does not separate into distinct
composition layers; thereby producing an improved dimensionally
stable foam.
[0047] As denoted in the preceding table, the different
combinations outlined by examples 1 through 4 have relatively
similar densities, but have some variations as to cream, gel and
tack free times. All of the examples exhibit phase stability; that
is, there is no separation into distinct layers for at least 24
hours after blending the resin components.
[0048] The present invention has been described in accordance with
the relevant legal standards, thus the foregoing description is
exemplary rather than limiting in nature. Variations and
modifications to the disclosed embodiment may become apparent to
those skilled in the art. Accordingly, the scope of legal
protection afforded this invention can only be determined by
studying the following claims.
* * * * *